package com.ld.igds.util;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.time.DateFormatUtils;
import org.apache.tomcat.util.codec.binary.Base64;

import sun.misc.BASE64Decoder;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.spec.SecretKeySpec;

import java.math.BigInteger;
import java.util.Date;

/**
 * @author Andy
 * @desc AES 工具类
 */
@SuppressWarnings("restriction")
public class AESUtil {

    private static final String KEY_ALGORITHM = "AES";
    private static final String CHARSET_NAME = "utf-8";
    private static final String ALGORITHMSTR = "AES/ECB/PKCS5Padding";

    /**
     * 将byte[]转为各种进制的字符串
     * @param bytes byte[]
     * @param radix 可以转换进制的范围，从Character.MIN_RADIX到Character.MAX_RADIX，超出范围后变为10进制
     * @return 转换后的字符串
     */
    public static String binary(byte[] bytes, int radix){
        // 这里的1代表正数
        return new BigInteger(1, bytes).toString(radix);
    }

    /**
     * base 64 encode
     * @param bytes 待编码的byte[]
     * @return 编码后的base 64 code
     */
    public static String base64Encode(byte[] bytes){
        return Base64.encodeBase64String(bytes);
    }

    /**
     * base 64 decode
     * @param base64Code 待解码的base 64 code
     * @return 解码后的byte[]
     * @throws Exception
     */
    public static byte[] base64Decode(String base64Code) throws Exception{
        return StringUtils.isEmpty(base64Code) ? null : new BASE64Decoder().decodeBuffer(base64Code);
    }


    /**
     * AES加密
     * @param content 待加密的内容
     * @param encryptKey 加密密钥
     * @return 加密后的byte[]
     * @throws Exception
     */
    public static byte[] aesEncryptToBytes(String content, String encryptKey) throws Exception {
        KeyGenerator kgen = KeyGenerator.getInstance(KEY_ALGORITHM);
        kgen.init(128);
        Cipher cipher = Cipher.getInstance(ALGORITHMSTR);
        cipher.init(Cipher.ENCRYPT_MODE, new SecretKeySpec(encryptKey.getBytes(), KEY_ALGORITHM));

        return cipher.doFinal(content.getBytes(CHARSET_NAME));
    }


    /**
     * AES加密为base 64 code
     * @param content 待加密的内容
     * @param encryptKey 加密密钥
     * @return 加密后的base 64 code
     * @throws Exception
     */
    public static String aesEncrypt(String content, String encryptKey)  {
        try{
            return base64Encode(aesEncryptToBytes(content, encryptKey));
        }catch (Exception e){
            e.printStackTrace();
            return "";
        }
    }

    /**
     * AES解密
     * @param encryptBytes 待解密的byte[]
     * @param decryptKey 解密密钥
     * @return 解密后的String
     * @throws Exception
     */
    public static String aesDecryptByBytes(byte[] encryptBytes, String decryptKey) throws Exception {
        KeyGenerator kgen = KeyGenerator.getInstance(KEY_ALGORITHM);
        kgen.init(128);
        Cipher cipher = Cipher.getInstance(ALGORITHMSTR);
        cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(decryptKey.getBytes(), KEY_ALGORITHM));
        byte[] decryptBytes = cipher.doFinal(encryptBytes);
        return new String(decryptBytes);
    }


    /**
     * 将base 64 code AES解密
     * @param encryptStr 待解密的base 64 code
     * @param decryptKey 解密密钥
     * @return 解密后的string
     * @throws Exception
     */
    public static String aesDecrypt(String encryptStr, String decryptKey) {
        try{
            return StringUtils.isEmpty(encryptStr) ? null : aesDecryptByBytes(base64Decode(encryptStr), decryptKey);
        }catch (Exception e){
            e.printStackTrace();
            return "";
        }
    }


    public static void main(String[] args) throws Exception {
        String content = "456";
        System.out.println("加密前：" + content);
        String encrypt = aesEncrypt(content, "bWFsbHB3ZA==WNST");
        encrypt = "Knk0iOvFAPzMay6++2CuVld6xOjmm3kisyTwgmORHnHaCvNv4TS4RDO/H8+A6DguUaRot65KMiA/DPcM+YdHn67qzzfVZKLiyboqdCeJKgIxamgvhC+KFoLNsvelwP4HasaX9egQ7H+bK7xGiWQPbvma80Q/YePoFP4CCD5PUVv22Tl0mmIkqYD6XFeHxg0GnFo1I1l75urH/7fCeyu2iZymvubir8MDr27wz4SxwDp7A7nqpYEa3S+kHpyGyvNJYcCFFvVnyZPOREyGD2Y5Nsk66jflsfJI9Jb6EiNvPAC+BhFF5XIwVARIx3FMc+JZRZQWlrAFSO3UdxmhhWruww==";
        System.out.println("加密后：" + encrypt);
        String decrypt = aesDecrypt(encrypt, "bWFsbHB3ZA==WNST");
        System.out.println("解密后：" + decrypt);

        Date date = new Date(1559989280*1000L);
        System.out.println("时间：" + DateFormatUtils.format(date,"yyyy-MM-dd HH:mm:ss"));
    }
}